Embodiments described herein relate generally to the remediation of electrochemical cell electrodes.
Batteries are typically constructed of solid electrodes, separators, electrolyte, and ancillary components, for example related to packaging, thermal management, cell balancing, consolidation of electrical current carriers into terminals, and/or other such components. Battery electrodes typically include active materials, conductive materials, binders (such as poly(vinylidene difluoride) (“PVDF”) and styrene-butadiene rubber (“SBR”)) and other additives that are calendered as a dried solid matrix coating onto a metallic substrate or current collector.
Some known methods for removing conventional electrode coatings involve immersion of the coatings in molten salt baths at very high temperatures (e.g., 450° C. or higher). Such methods have been found to cause damage to/erosion of the underlying current collector, and subsequent recovery of the coating constituents from the molten salt bath has been found to be uneconomical. Other approaches have involved the dissolution/leaching of electrode materials in strong acids. The use of harsh chemical treatments is necessary due to the difficulty of mechanically separating electrode components in a conventional electrode coating due both to the presence of large amounts of binder materials and also due to the hardness and density of the coating after the mechanical calendaring process. Still other approaches have involved electrolysis-based recovery of metals, requiring high power consumption and large investments in equipment, while resulting in large quantities of unrecovered electrode components.
Improved methods of remediating electrochemical cell electrodes are economically and environmentally desirable.